mm, page_alloc: add static key for should_fail_alloc_page()

Similarly to should_failslab(), remove the overhead of calling the
noinline function should_fail_alloc_page() with a static key that guards
the callsite in the page allocator hotpath, and is controlled by the
fault and error injection frameworks and bpf.

Additionally, compile out all relevant code if neither
CONFIG_FAIL_ALLOC_PAGE nor CONFIG_FUNCTION_ERROR_INJECTION is enabled.
When only the latter is not enabled, make should_fail_alloc_page()
static inline instead of noinline.

No measurement was done other than verifying the should_fail_alloc_page
is gone from the perf profile. A measurement with the analogical change
for should_failslab() suggests that for a page allocator intensive
workload there might be noticeable improvement. It also makes
CONFIG_FAIL_ALLOC_PAGE an option suitable not only for debug kernels.

Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>